Surgical procedures are used to treat and cure a wide range of diseases, conditions, and injuries. Surgery often requires access to internal tissue through open or minimally invasive surgical procedures. The term “minimally invasive” refers to all types of minimally invasive surgical procedures, including endoscopic, laparoscopic, arthroscopic, natural orifice intraluminal, and natural orifice transluminal procedures. Minimally invasive surgery can have numerous advantages compared to traditional open surgical procedures, including reduced trauma, faster recovery, reduced risk of infection, and reduced scarring.
In many minimally invasive procedures, the abdominal cavity is insufflated with carbon dioxide gas to provide adequate space to perform a procedure. The insufflated cavity is generally under pressure and is sometimes referred to as being in a state of pneumoperitoneum. Surgical access devices are often used to facilitate surgical manipulation of internal tissue while maintaining pneumoperitoneum. For example, during a surgical procedure the abdominal wall can be pierced and a cannula or trocar (such as the trocar shown in FIGS. 1A-2) can be inserted into the abdominal cavity. The trocar can provide a port through which other surgical instruments can be passed into a patient's body to perform a variety of procedures.
Development in minimally invasive surgery has resulted in increasingly complex procedures that require multiple instruments and precise manipulations within the body. Because of the limited access space afforded by a trocar and the relatively larger wound size associated therewith, one solution has been the use of percutaneous surgical instruments inserted directly into a body cavity and used to supplement instruments introduced through one or more trocars. For example, procedures have been developed that involve additional percutaneous instruments to aid in retracting organs and structures. In some procedures, one or more percutaneous instruments having removable end effectors are utilized in combination with a trocar that can accommodate the passage of various end effectors for connection with the instrument in vivo. Inserting surgical instruments percutaneously, i.e., passing directly through tissue without an access device, can further reduce trauma and scarring to the patient by reducing the size of the wound created. Additional details on such instruments can be found, for example, in U.S. Patent Application Publication No. 2011/0087267 to Spivey et al., entitled “Method For Exchanging End Effectors In Vivo,” which is hereby incorporated by reference.
The increasing use of percutaneously-inserted surgical instruments is not without challenges, however. For example, the use of percutaneously-inserted surgical instruments can require a large operating staff to simultaneously manipulate the percutaneously-inserted instrument, the trocar providing access to pass an end effector, and a loading device used to deliver the end effector through the trocar and attach it to the distal end of the instrument. The complexity of this operation is compounded when several end effectors are used in sequence to accomplish different tasks (e.g., grasping, cutting, etc.). In such a case, a surgeon or other user is forced to juggle the plurality of end effectors along with at least one loading device, trocar, and percutaneous instrument.
In addition, it can be difficult to successfully attach or remove an end effector from a percutaneously-inserted instrument inside a patient's body. There are a number of reasons for this, not the least of which is the confined and remote environment in which the instrument shaft and end effector are being manipulated. Surgeons can struggle to ensure that the straight shaft of the surgical trocar and the straight shaft of the percutaneous instrument are in alignment when coupling or decoupling an end effector. Moreover, it can be difficult in this confined environment to determine when an end effector is completely and successfully coupled to a percutaneous instrument and/or a loading device. Making this determination can be important, however, because prematurely releasing an end effector from one instrument before coupling it to another can drop the end effector within the body cavity, necessitating further time and action to retrieve it.
One attempted solution to these challenges has been to utilize the trocar as a means for passing the distal end of a percutaneously-inserted instrument back out of a patient's body in order to exchange end effectors. Passing the instrument (either with or without an end effector attached) through the trocar in the “wrong” direction (i.e., from its distal end toward its proximal end) can damage the one or more seals present in the trocar that help maintain pneumoperitoneum. This is because trocar seals are often designed with a “duckbill” or other shape that is oriented for proximal-to-distal instrument passage.
Accordingly, there is a need for improved devices and methods that assist users in managing a number of modular surgical end effectors and passing them into a patient's body for attachment to a surgical instrument positioned inside the body. There is also a need for improved devices and methods that provide better feedback to a user regarding the coupling (or lack thereof) between an end effector and another instrument.